Pen



FIG. 1 is a perspective view of a pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a back elevational view thereof;

FIG. 4 is a right-side elevational view thereof;

FIG. 5 is a left-side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a perspective view of the pen showing the pen and cap separated from each other.

The broken lines in the drawings depict part of the pen that forms no part of the claimed design. 

CLAIM The ornamental design for a pen, as shown and described. 